While there is much prior art regarding marine propulsion and transport, propulsion systems for boats have yet to progress beyond the use of propellers, which remain the primary drive for naval vessels. Even the ideal propeller is still an inefficient device and the traditional vessel hull requires rapid increases in power as speed rises. A small pleasure ski boat at 30 mph gets the same fuel economy as a semi truck on the highway. Even modern propellers can have significant cavitation-producing slippage, especially during acceleration. Design characteristics of propellers prevent a single propeller design from achieving low-speed thrust and lift, while still allowing the craft to achieve high maximum speeds. Propellers are similarly limited in their application to amphibious operations or those requiring a vessel to enter shallow depths or waters of unknown composition. Further, noise generated from cavitation, shear and water slippage over propellers can be detected readily.
Challenges arising from adverse aquatic conditions that affect the efficiency of propulsions systems have been present since the first seagoing vessel attempted to navigate rough waters. The unpredictable nature of weather, the presence of waves, and other adverse oceanic conditions have long presented obstacles to those who have attempted to increase the efficiency of naval propulsion systems or the accuracy of navigational methods. None of the prior art has been particularly effective at reducing the myriad of problems caused by waves and rough waters in general. The typical solution to dealing with waves has been to design larger vessels with deep v-type hulls, which require more power and fuel, and still exhibit movement when waves are encountered. The use of such hulls also prevents effective navigation in shallow waters, which in turn limits the effective utility of the vessel.
Friction drag is a force comprised of fluid pressure and shear stress components exerted on a body as it moves through the fluid. Drag can vary greatly in magnitude with velocity and shape of the body. As a ship moves through the water, it creates a water boundary layer that is dragged along with it. The boundary layer is created from the friction between the hull and the displacement of water to the sides of the vessel as it moves through the water. The size of this boundary layer increases with the vessels velocity. Friction drag theoretically increases to the second power of the velocity. As the layer grows in size the vessels effective friction drag surface area is increased, subsequently increasing the fiction force greatly. This friction drag slows the vessel down and requires more power and fuel to achieve higher speeds or traverse necessary distances than if the drag component were reduced. The use of bubbles to reduce friction drag has been proposed, but no one has yet developed a way to effectively implement their use on full size naval vessels. A vessel that could ride on the water surface (instead of being pushed through the water) would eliminate virtually all of the friction drag imposed on tradition navel vessel designs.
This invention eliminates many of these problems by utilizing one or more suspended belt drives to efficiently engage the water and provide for variable speed, thrust, and lift characteristics that changing circumstances and various aquatic environments may require. The suspended belt drives used in this invention can be effectively insulated from the adverse effects caused by waves and rough waters since the drives can be housed in open-bottomed enclosures that allow the drive belts to engage the water in a consistent and efficient manner. An air bearing system incorporated into the drive units will both pressurize the enclosure as well as discharge air bubbles that will reduce the friction drag of the attached enclosure. This feature is assisted by the inclusion of one of several various types of suspension between both the drive unit and the enclosure and the enclosure and the main body of the vessel. Thus, the enclosure is able to move up and down while maintaining a constant buoyancy force. This both helps maintain a more constant, smoother water surface inside the enclosure and stabilize the main body from the effects of waves
The use of open-bottomed enclosures as primary flotation components eliminates much of the hull surface area and thus friction. The use of suspension allows the enclosure to provide a constant lift to the main body and maintain a more constant wetted outer hull waterline. The draft of the enclosure can be changed as sea conditions warrant. This invention attempts to reduce water friction as much as possible, with small vessels able to run on top of the water at high speed with much higher efficiency than current designs are able to attain. By increasing the efficiency and effectiveness of the propulsion systems for naval vessels, faster and longer-range ships that consume less fuel are possible.